Here’s why Tim Walz and J.D. Vance loving Diet Mountain Dew could actually hurt the brand

First, Republican vice-presidential candidate J.D. Vance

talked up Diet Mountain Dew while on the campaign trail. Now we’re discovering that Tim Walz, the newly announced Democratic veep contender, is a big-time fan of the soft drink as well.

While that all may seem like good exposure for Mountain Dew — one of the prominent fixtures in PepsiCo Inc.’s PEP family of brands — some marketing and beverage-industry experts say it might have the opposite effect.